The Rat Emporium Toronto has retired from breeding.
Two ratteries that I have personally worked with and I would recommend adopting from are True North Rattery and Rambling Rats. True North Rattery has the descendants of all of my heart rats, and has some of the most excitable puppy-like rats I’ve ever seen. They absolutely love people. Rambling Rats has some very unique breeds of ratties, and her rats are big and cuddly and sweet!
Two ratteries that I haven’t worked with as much but have heard great things of are Georgian Bay Rattery and Atlantis Rattery! If I had continued breeding I would have absolutely wanted to work with them, many people have adopted fantastic pets from them!